13.6.1 新添加一个界面(Adding One Interface) 简单

//13.6 系统扩展(System Extension)
//13.6.1 新添加一个界面(Adding One Interface)
//添加一个sony2.h 做为调整亮度的操作，他继承者sony.h
//由Sony派生Sony2

#include "createsony.h"
#include "sony.h"
enum Technology{PUREFLAT,PLASMA,LIQUIDCRYSTAL};
void fn(Sony* s)
{
	Sony2 * ps2 = dynamic_cast<Sony2*>(s); //增加
	if(ps2) ps2->adjustLight(); //否则不用
	ps2->adjustVolume();
	ps2->switchChannel();
}

void createSonyObject(CreateSony* sp)
{
	Sony* s29 = createSonyInch29(sp);
	fn(s29);
	delete s29;
}

#include <iostream>
using namespace std;
int main()
{
	if(CreateSony* sp = createCreateSony(LIQUIDCRYSTAL)){
	    createSonyObject(sp);
		delete(sp);
	}
	system("pause");
	return 0;
}

　　

#ifndef HEADER_SONY2
#define HEADER_SONY2
#include "sony.h"

class Sony2 : public Sony
{
public:
	virtual void adjustLight() =0;
};
#endif;/**/